How to use the @pixi/constants.ENV.WEBGL2 function in @pixi/constants

export function getTestContext()
{
    if (context === unknownContext || (context && context.isContextLost()))
    {
        const canvas = document.createElement('canvas');

        let gl;

        if (settings.PREFER_ENV >= ENV.WEBGL2)
        {
            gl = canvas.getContext('webgl2', {});
        }

        if (!gl)
        {
            gl = canvas.getContext('webgl', {})
            || canvas.getContext('experimental-webgl', {});

            if (!gl)
            {
                // fail, not able to get a context
                gl = null;
            }
            else
            {

* The maximum support for using WebGL. If a device does not
 * support WebGL version, for instance WebGL 2, it will still
 * attempt to fallback support to WebGL 1. If you want to
 * explicitly remove feature support to target a more stable
 * baseline, prefer a lower environment.
 *
 * Due to {@link https://bugs.chromium.org/p/chromium/issues/detail?id=934823|bug in chromium}
 * we disable webgl2 by default for all non-apple mobile devices.
 *
 * @static
 * @name PREFER_ENV
 * @memberof PIXI.settings
 * @type {number}
 * @default PIXI.ENV.WEBGL2
 */
settings.PREFER_ENV = isMobile.any ? ENV.WEBGL : ENV.WEBGL2;

/**
 * If set to `true`, Textures and BaseTexture objects stored
 * in the caches ({@link PIXI.utils.TextureCache TextureCache} and
 * {@link PIXI.utils.BaseTextureCache BaseTextureCache}) can *only* be
 * used when calling {@link PIXI.Texture.from Texture.from} or
 * {@link PIXI.BaseTexture.from BaseTexture.from}.
 * Otherwise, these `from` calls throw an exception. Using this property
 * can be useful if you want to enforce preloading all assets with
 * {@link PIXI.Loader Loader}.
 *
 * @static
 * @name STRICT_TEXTURE_CACHE
 * @memberof PIXI.settings
 * @type {boolean}
 * @default false

createContext(canvas, options)
    {
        let gl;

        if (settings.PREFER_ENV >= ENV.WEBGL2)
        {
            gl = canvas.getContext('webgl2', options);
        }

        if (gl)
        {
            this.webGLVersion = 2;
        }
        else
        {
            this.webGLVersion = 1;

            gl = canvas.getContext('webgl', options)
            || canvas.getContext('experimental-webgl', options);

            if (!gl)

createContext(canvas, options)
    {
        let gl;

        if (settings.PREFER_ENV >= ENV.WEBGL2)
        {
            gl = canvas.getContext('webgl2', options);
        }

        if (gl)
        {
            this.webGLVersion = 2;
        }
        else
        {
            this.webGLVersion = 1;

            gl = canvas.getContext('webgl', options)
            || canvas.getContext('experimental-webgl', options);

            if (!gl)